Hydraulic press

ABSTRACT

An apparatus for increasing the force exerted by a hydraulic press. A pair of headers are mounted on the upper platen of the press and rods extend downwardly from each header and carry blocks that are adapted to be received within pockets in the lower platen. When the upper platen is lowered toward the lower platen and the cooperating dies carried by the platens engage the workpiece, the blocks are automatically locked within the pockets to integrally connect the headers to the lower platen. Auxilliary cylinders mounted on the upper platen exert an upward force against the headers forcing the headers upwardly and thereby increasing the force applied to the workpiece.

United States Patent [191 Olson 4 1 Feb. 26, 1974 [75] Inventor:

[52] US. Cl. 100/269 R, 72/453 [51] Int. Cl B30b 1/32 [58] Field ofSearch 100/214, 269 R; 72/453 [56] References Cited UNITED STATESPATENTS 1,866,559 7/1932 Glasner et al 100/214 UX 3,010,432 11/1961Robra et al. 100/269 R X 3,375,709 4/1968 Holmes 100/214 X 3,495,5262/1970 Mohler et a1. 100/269 R X 3,673,849 7/1972 Voitsekhovsky et a172/453 X Primary Examiner-Edward L. Roberts Assistant Examiner-Philip R.Coe

Attorney, Agent, or F irm-Andrus, Sceales, Starke & wi l.-.

[57] ABSTRACT An apparatus for increasing the force exerted by ahydraulic press. A pair of headers are mounted on the upper platen ofthe press and rods extend downwardly from each header and carry blocksthat are adapted to be received within pockets in the lower platen. Whenthe upper platen is lowered toward the lower platen and the cooperatingdies carried by the platens engage the workpiece, the blocks areautomatically locked within the pockets to integrally connect theheaders to the lower platen. Auxilliary cylinders mounted on the upperplaten exert an upward force against the headers forcing the headersupwardly and thereby increasing the force applied to the workpiece.

13 Claims, 3 Drawing Figures HYDRAULIC PRESS BACKGROUND OF THE INVENTIONThe capacity of a hydraulic press is limited by the size of thehydraulic cylinder, the horse power of the motor,

the pump size, and the strength of the structural components such as thetie rods. Recently, in the molding of plastic articles, there has beenincreased emphasis on the use of higher pressures, and modification ofan existing press to achieve higher pressures is a costly operation. Amodification to obtain higher capacities may require the use of a largercylinder which in turn may necessitate the use of a larger motor andpump as well as stronger structural components. The result is that inmany cases, the cost of modifying an existing press to achieve a highercapacity may be nearly equal to the cost of a new high capacity press.Thus, modifications of a press to obtain higher capacities is, in mostcases, not economically practical.

SUMMARY OF THE INVENTION The invention relates to an inexpensiveattachment for an existing hydraulic press for increasing the forceexerted by the press without the necessity of increasing the cylindersize, the horse power of the motor, or the pump size. According to theinvention, a pair of headers are mounted on the upper platen of thepress and rods extend downwardly from each header and carry blocks orshoes which are adapted to be received within pockets in the lowerplaten. When the upper platen is lowered toward the lower platen and thecooperating dies carried by the platens are brought into engagement withthe workpiece, the blocks are automatically locked within the pockets tointegrally connect the headers to the lower platen.

With the blocks locked in the pockets, auxilliary cylinders mounted onthe upper platen are actuated which exert an upward force against theheaders, thereby forcing the headers upwardly and increasing the forceapplied to the workpiece.

The construction of the invention enables the tonnage or force exertedby a standard hydraulic press to be substantially increased withoutincreasing the size of the hydraulic cylinder, the horse power of themotor, the pump size, or the size of the tie rods. The system of theinvention can be selectively operated, meaning that the existing presscan be operated, if desired, without the auxilliary system, or theexisting press can be utilized in combination with the auxilliarysystem.

The construction of the invention can be installed with existinghydraulic presses at low cost, or alternately can be combined with newpress constructions.

Other objects and advantages will appear in the course of the followingdescription.

DESCRIPTION OF THE DRAWINGS I FIG. 1 is a perspective view of a standardhydraulic press incorporating the auxilliary system of the inventionwith the press in the partially open position;

FIG. 2 is an end view of the press with the upper platen in the raisedposition; and

FIG. 3 is a view similar to FIG. 2 showing the upper platen in thelowered position and the auxilliary cylinders operating to increase theforce exerted between the platens.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings illustrate atypical hydraulic press including a lower platen l and an upper platen2. The upper platen is moved toward and away from the lower platen bymeans of hydraulic cylinders 3, and the upper platen is guided invertical movement by a series of vertical guide rods 4 that extendupwardly from the lower platen.

Suitable dies are mounted on the upper and lower platen, respectively,and as the upper platen is lowered toward the lower platen 1 a workpiecewill be engaged by the mating dies in a conventional manner.

According to the invention, a pair of generally boxshaped headers 5 aremounted at the opposite ends of the upper platen 2. When the upperplaten 2 is in the upper or raised position, the ends of the header 5rest on vertical plates 6 that are supported on a horizontal plate 7carried by the longitudinal stringers 8 of upper platen 2. Suitable webplates 9 are secured to the lower portion of the plate 7 to provideadequate reinforcement.

Each of the headers 5 is provided with a pair of side walls 10 which arejoined together at their ends by an end wall 11. A pair of generallyrectangular blocks or shoes 12 are located within the interior of eachheader 5, and rods 13 are threaded within openings in the blocks 12 andextend downwardly through the plate 7. To secure the blocks 12 to theheader 5, each block is formed with a hole 15, while the side walls 10of the header are provided with two sets of vertically disposed holes16. A pin 17 is inserted through one set of the aligned holes 16, aswell as through the hole 15 to lock the block 12 to the header 5. Theuse of the pair of holes 16 in each side wall 10 provides a degree ofadjustment for the position of the block 12. By inserting the pin 17through the uppermost holes 16, the block will be positioned in an upperposition, while utilizing the lowermost holes 16 will result in theblock 12 being located in a lower position.

Each of the rods 13 extends through a bushing 18 mounted on the baseplate 7 and the lower end of the rod is threaded within an opening in ashoe or block 19. When the upper platen is in the fully raised positionthe shoes 19 will be located a substantial distance above the lowerplaten and as the upper platen is lowered the shoes 19 will be receivedwithin recesses or pockets 20 formed in housings 21 secured to the lowerplaten 1. As best shown in FIG. 2, each of the housings 21 is generallyrectangular in shape having four side walls 22 and a bottom 23 which iswelded to the lower portions of the side walls.

The shoes 19 are adapted to be locked within the recesses 20 in housings21 by locking pins 24 each of which is carried by ram or piston rod 25that is slidable within a cylinder 26. The cylinders 26 at each end ofthe press are supported from a mounting bracket 27 attached to the lowersurface of base plate 28 of the lower platen 1.

Walls 22 are provided with aligned openings 29 and each shoe 19 isformed with an elongated opening 30 that is adapted to register withopenings 29 when the shoe is received within the pocket 20. By extendingthe piston rods 25, the pins 24 will be inserted in the aligned openings29 and 30 to lock shoes 19 within the pockets 20. Thus, with the pins 24in the locked posi tion, as shown in FIG. 3, the rod 13 and headers 5will be integrally connected to the lower platen 1.

A pair of auxilliary hydraulic cylinders 31 are mounted on the plate 7between the rods 13. The ram of piston rod 32 of each cylinder isthreaded within the opening in a block 33 which is secured within theheader 5 in the same manner that the blocks 12 are secured to theheader. More specifically, each block 33 is provided with an opening 34that can be brought into registry with one of two sets of alignedopenings 35 in the side wall of the header. A pin 36 is adapted to beinserted within the aligned openings 34 and 35 to lock the block 33 withrespect to the header 5.

When the press is open and the upper platen is in the raised position,the headersS will be supported on the upper edges of the vertical plate6 and the shoes 19 will be located a substantial distance above thehousing 21. As the upper platen 2 is lowered toward the lower platen 17and the dies carried by the platens are brought into mating engagement,the shoes 19 will be received within the recesses 20, and when the holes29 and 30 are in alignment, a limit switch is actuated to operate thecylinders 26 and force the locking pins 24 outwardly into the alignedopenings 29 and 30, thereby locking the shoes 19, rods 13 and headers 5to the lower platen.

With the headers 5 integrally secured to the lower platen 1, theauxilliary cylinders 31 are then actuated forcing the rams 32 upwardlyagainst the headers 5, causing the headers to move upwardly with respectto the plate 6. As the headersS are integrally connected to the lowerplaten, this produces an increased force between the platens l and 2.

After the pressing operation is completed, the fluid pressure to thecylinders 3 is reversed which acts to raise the upper platen. On initialupward movement of the upper platen 2, the cylinders 26 are actuated torelease the locking pins 24. The initial upward movement of the platen 2serves to remove the weight from the pins 24 so that they can be moreeasily withdrawn from the aligned holes 29 and 30. After the lockingpins 24 are released, the bottom of the shoes 19 react against thebottom wall 23 of housing 21 to increase the stripping force to part thedies. After stripping, the hydraulic pressure to the auxilliarycylinders 31 is released so that the headers 5 will move downwardly bygravity until they are again supported on the upper edge of the plates6.

The construction of the invention provides a substantial increase intonnage or force so that the force exerted by a press may be increasedtwo or three fold. The increased tonnage can be achieved without anincrease in horse power, pump size or size of the main tie rods.

Due to the use of the blocks 12 and 33, along with the vertically spacedopenings in the headers 5, a degree of adjustment is achieved so thatthe unit can be utilized for various sized dies.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim: g

1. In a hydraulic press construction, an upper platen, a lower platen,means for moving the upper platen toward and away from said lowerplaten, connecting means having one end connected to one of said platensand extending in a direction towardvthe other platen with the oppositeend of said connecting means projecting beyond said other platen,abutment means secured to the projecting end of said connecting meansand movably mounted with respect to said other platen, and meansreacting between said abutment means and said other platen for movingthe abutment means in a direction away from said other platen to therebyincrease the force exerted between said upper and lower platen.

2. The construction of claim 1. wherein said means for moving theabutment means is a hydraulic cylinder unit.

3. The construction of claim 1, wherein said connecting means comprisesa plurality of rods with one end of each rod connected to said firstnamed platen, said rods extending through openings in said other platenand the opposite ends of said rods being connected to said abutmentmeans.

4. The construction of claim 3, and including guide means separate fromsaid rods for guiding the upper platen in movement toward and away fromsaid lower platen.

5. In a hydraulic press construction, an upper platen, a lower platen,means for moving the upper platen toward and away from said lower platento provide a pressing force on a workpiece disposed between saidplatens, a header disposed above the upper platen and movably mountedwith respect to said upper platen, a series of rods, the upper end ofeach rod being secured to said header, locking means for removablyconnecting the lower end of each rod to the lower platen, and hydraulicmeans reacting between the upper platen and said header for moving saidheader upwardly in a direction away from said upper platen when saidrods are secured to said lower platen to thereby increase the pressingforce exerted between said platens.

6. The press construction of claim 5, wherein each rod is mounted forsliding movement within an opening in said upper platen.

7. The press construction of claim 5 in which the upper end of each rodis adjustably connected to the header.

8. The press construction of claim 5, wherein the lower platen isprovided with a plurality of pockets and the lower end of each rodcarries a shoe disposed to be received in a pocket as the upper platenis lowered toward said lower platen, said locking means comprising a pindisposed to be inserted within aligned openings in said pocket and saidshoe to thereby secure the rod to said lower platen.

9. The press construction of claim 8, and including second hydraulicmeans operably connected to each pin for moving the pin into lockingengagement and for releasing the pin from locking engagement.

10. The press construction of claim 8, wherein each pocket is borderedby a bottom wall, said shoes reacting against said bottom walls afterwithdrawal of said locking pins to aid in separation of the platens.

11. The press construction of claim 5, wherein said hydraulic meansincludes a cylinder mounted on the upper platen and a ram slidablewithin the cylinder and reacting against said header.

12. The press construction of claim 11, and including a block secured tothe ram, and means for securing said block to said header.

13. The press construction of claim 5, and including guide meansseparate from said rods for guiding the upper platen in movement withrespect to the lower platen.

1. In a hydraulic press construction, an upper platen, a lower platen,means for moving the upper platen toward and away from said lowerplaten, connecting means having one end connected to one of said platensand extending in a direction toward the other platen with the oppositeend of said connecting means projecting beyond said other platen,abutment means secured to the projecting end of said connecting meansand movably mounted with respect to said other platen, and meansreacting between said abutment means and said other platen for movingthe abutment means in a direction away from said other platen to therebyincrease the force exerted between said upper and lower platen.
 2. Theconstruction of claim
 1. wherein said means for moving the abutmentmeans is a hydraulic cylinder unit.
 3. The construction of claim 1,wherein said connecting means comprises a plurality of rods with one endof each rod connected to said first named platen, said rods extendingthrough openings in said other platen and the opposite ends of said rodsbeing connected to said abutment means.
 4. The construction of claim 3,and iNcluding guide means separate from said rods for guiding the upperplaten in movement toward and away from said lower platen.
 5. In ahydraulic press construction, an upper platen, a lower platen, means formoving the upper platen toward and away from said lower platen toprovide a pressing force on a workpiece disposed between said platens, aheader disposed above the upper platen and movably mounted with respectto said upper platen, a series of rods, the upper end of each rod beingsecured to said header, locking means for removably connecting the lowerend of each rod to the lower platen, and hydraulic means reactingbetween the upper platen and said header for moving said header upwardlyin a direction away from said upper platen when said rods are secured tosaid lower platen to thereby increase the pressing force exerted betweensaid platens.
 6. The press construction of claim 5, wherein each rod ismounted for sliding movement within an opening in said upper platen. 7.The press construction of claim 5 in which the upper end of each rod isadjustably connected to the header.
 8. The press construction of claim5, wherein the lower platen is provided with a plurality of pockets andthe lower end of each rod carries a shoe disposed to be received in apocket as the upper platen is lowered toward said lower platen, saidlocking means comprising a pin disposed to be inserted within alignedopenings in said pocket and said shoe to thereby secure the rod to saidlower platen.
 9. The press construction of claim 8, and including secondhydraulic means operably connected to each pin for moving the pin intolocking engagement and for releasing the pin from locking engagement.10. The press construction of claim 8, wherein each pocket is borderedby a bottom wall, said shoes reacting against said bottom walls afterwithdrawal of said locking pins to aid in separation of the platens. 11.The press construction of claim 5, wherein said hydraulic means includesa cylinder mounted on the upper platen and a ram slidable within thecylinder and reacting against said header.
 12. The press construction ofclaim 11, and including a block secured to the ram, and means forsecuring said block to said header.
 13. The press construction of claim5, and including guide means separate from said rods for guiding theupper platen in movement with respect to the lower platen.